Trochoidal gear, fluid displacement pumps and engines are well-known in the art. In general, a lobate, eccentrically-mounted, inner male rotor interacts with a mating lobate female outer rotor in a close-fitting chamber formed in a housing with a cylindrical bore and two end plates. The eccentrically mounted inner rotor gear has a set number of lobes or teeth and cooperates with a surrounding outer lobate rotor, i.e., ring gear, with one additional lobe or tooth than the inner rotor. The outer rotor gear is contained within the close fitting cylindrical enclosure.
The inner rotor is typically secured to a drive shaft and, as it rotates on the drive shaft, it advances one tooth space per revolution relative to the outer rotor. The outer rotor is rotatably retained in a housing, eccentric to the inner rotor, and meshing with the inner rotor on one side. As the inner and outer rotors turn from their meshing point, the space between the teeth of the inner and outer rotors gradually increases in size through the first one hundred eighty degrees of rotation of the inner rotor creating an expanding space. During the last half of the revolution of the inner rotor, the space between the inner and outer rotors decreases in size as the teeth mesh.
When the device is operating as a pump, fluid to be pumped is drawn from an inlet port into the expanding space as a result of the vacuum created in the space as a result of its expansion. After reaching a point of maximum volume, the space between the inner and outer rotors begins to decrease in volume. After sufficient pressure is achieved due to the decreasing volume, the decreasing space is opened to an outlet port and the fluid forced from the device. The inlet and outlet ports are isolated from each other by the housing and the inner and outer rotors.
For traditional configurations, it may be difficult for fluid to fill a desired chamber under many desirable operating conditions, resulting in greatly reduced efficiency. There is therefore a need for improved fluid flow to create a more efficient device.